Abstract:

The sensitivity of debris flow to different lithology is significantly different,and the rock is difficult to use in debrisrelated research quantitatively.Taking the Three Rivers Parallel Area as the study area,the lithology is divided into 14 engineering geological rock groups by using the division method.By introducting the lithology sensitivity formula〖WTBX〗 Fn = Nn / Sn〖WTBZ〗, the relationship between debris flows and rock groups in the study area is analyzed,and the sensitivity of debris flow to the rock groups is calculated.Supported by ArcGIS 90,the lithology is classified into 4 levels according to the sensitivity,and the classification results are applied to the risk assessment of debris flow in the study area.The paper chooses slope, lithology,fracture,vegetation and human activity as debris flow risk evaluations,establishes the debris flow risk assessment model,and obtains the hazard zonation map of the study area in support of GIS technology.The results coincides with the actual disasters,fully proving that this methodology is feasible,which can provide guidance and reference for geological hazard assessment,disaster prevention and mitigation in Southwest China